Diaporthe yunnana Y. Zhang ter & L. L. Zhao, 2025

Diaporthe yunnana Y. Zhang ter & L. L. Zhao sp. nov.

Fig. 6 View Figure 6

Etymology.

Named after the place, Yunnan, where the fungus was abundantly found.

Description.

Sexual morph: not observed. Asexual morph: Conidiomata pycnidial, produced on PDA, globose or irregular, solitary, dark brown to black, 290–810 μm diam. Conidiophores hyaline, smooth, densely aggregated, 12–20.5 × 1.5–3 μm; Conidiogenous cells phialidic, hyaline, terminal, cylindrical, 5.5–10 × 1.5–2.5 μm diam, tapered towards the apex. Alpha conidia hyaline, aseptate, ellipsoid to cylindrical, obtuse at both ends, multi-guttulate, 6–10.5 × 2–3 μm (mean ± SD = 8.5 ± 1.0 × 2.8 ± 0.2 μm, n = 30). Beta conidia hyaline, aseptate, filiform, curved, tapering towards both ends, multi-guttulate, 25.5–42 × 1–1.7 μm (mean ± SD = 34.5 ± 3.6 × 1.4 ± 0.2 μm, n = 30). Gamma conidia infrequent, hyaline, aseptate, botuliform, tapering towards both ends, multi-guttulate, 12.5–18 × 2–2.5 μm (mean ± SD = 14.0 ± 1.5 × 1.9 ± 0.1 μm, n = 30).

Culture characteristics.

On PDA, colony at first flat with white felty mycelium, becoming brown in the center, flourishing at center of colony, reverse white to brown. On MEA, white on surface, reverse white to dark brown. Colonies cover the Petri dish diameter on PDA and reach 57 mm in diameter on MEA.

Material examined.

China • Yunnan Province, Kunming City , from diseased branches of J. regia , Y. Ding, M. Li and L. L. Zhao, 23 February 2024 ( holotype YN-12, ex-type culture CGMCC 3.27754 View Materials ; other culture CGMCC 3.27756 View Materials ) .

Notes.

Multi-locus phylogenetic analysis indicated that Diaporthe yunnana formed a moderately supported subclade with D. gammata (77 % / 0.79 / 74 %) (Fig. 2 View Figure 2 ). Morphologically, D. yunnana can be readily distinguishable from D. gammata by its shorter beta conidia (25.5–42 × 1–1.7 vs. 29–48.5 × 1–2 μm) and smaller-size gamma conidia (12.4–18.2 × 1.8–2.3 vs. 16–31.5 × 1.5–4 μm) ( Xiao et al. 2023). Based on nucleotide base comparison, D. yunnana can be distinguished from D. gammata by base differences as follows: 13 / 548 bp for ITS (2.37 %), 18 / 440 bp for his 3 (4.08 %), 23 / 360 bp for tef 1 - α (6.39 %), and 8 / 486 bp for tub 2 (1.65 %) ( Xiao et al. 2023).